Multiple encapsulated sweetener delivery system

ABSTRACT

A chewing gum composition having prolonged sweetness duration through the incorporation of a delivery system comprising a high intensity sweetener encapsulated in a first core coating comprising a low molecular weight polyvinylacetate material and a second outer hydrophilic coating. The resulting delivery system provides improved up front sweetness delivery combined with improved thermal stability and corresponding versatility of end use.

RELATED APPLICATIONS

The present Application is a Continuation-in-Part of Co-pendingapplication Ser. No. 945,743, filed Dec. 23, 1986 now U.S. Pat. No.4,816,265 in the names of Subraman Rao Cherukuri and Gul Mansukhani.Applicants claim the benefit of this application under 35 U.S.C. 120.

BACKGROUND OF THE INVENTION

The present invention relates generally to a sweetener delivery systemand, more particularly, to an artificial sweetener composite that offersa combination of controlled release with improved stability and shelflife.

Numerous patents have disclosed coatings for sweeteners in an attempt todelay or prolong sweetness, as well as to stabilize those sweeteners,such as aspartame, which are sensitive to moisture, temperature and pH.U.S. Pat. No. 4,384,004 to Cea et al. discloses solid particles ofaspartame encapsulated by a coating material selected from the groupconsisting of cellulose, cellulose derivatives, arabinogalactin, gumarabic, polyolefins, waxes, vinyl polymers, gelatin, zein and mixturesthereof, wherein the amount of said coating material to said methylester is from 1:1 to 1:10. More particularly, the coating materialsinclude cellulose, methyl cellulose, ethyl cellulose, cellulose nitrate,cellulose acetate phthalate, carboxymethyl cellulose, hydroxyethylcellulose, hydroxypropyl cellulose, arabinogalactin; polyethylene,polymethacrylates, polyamides, ethylene-vinyl acetate copolymers,polyvinylpyrrolidone; gum arabic, paraffin wax, carnauba wax,spermaceti, beeswax; stearic acid, steryl alcohol, glyceryl stearate;gelatin, zein and mixtures thereof.

The method of coating employed in this reference includes suspending theaspartame particles in a stream of air that passes through a zone ofatomized liquid droplets of the coating material, so that the coatingmaterial is deposited on the surface of the aspartame. More than onecoating may be used, and in such instance, the inner coating ispreferably water-soluble and the outer coating is preferablywater-insoluble.

U.S. Pat. Nos. 4,122,195 and 4,139,939, both to Bahoshy et al., fixaspartame by preparing it with a material such as gum arabic or thereaction product of a compound containing a polyvalent metallic ion,with an ungelatinized starch acid-ester of a substituted dicarboxylicacid, by a spray drying technique, where the aspartame and a film formerare prepared in an emulsion.

U.S. Pat. No. 4,374,858 to Glass et al. discloses an aspartame sweetenedchewing gum having improved sweetness stability wherein the chewing gumpiece has aspartame coated on its surface, as opposed to incorporatingit in the chewing gum mix.

European patent application No. 81110320.0, published June 16, 1982(Publication No. 0053844) to Ajinomoto Co., Inc., discloses a stabilizeddipeptide-based sweetening composition comprising (1) from 20 to 60% byweight of solid fat, (b) from 10 to 30% by weight emulsifier, (c) from10 to 30% by weight polysaccharide and (d) not more than 30% by weightof dipeptide sweetener. The compositions are prepared by heating themixture of the ingredients, cooling, and pulverizing to obtain powder orgranules of the composition to obtain an ASTM mesh size of smaller than12. Spray drying the mixture is also disclosed.

U.S. Pat. No. 4,105,801 to Degliotti discloses a confection comprising acore portion and a shell adherently enveloping the core portion, wherebythe shell is formed by an intimate mixture of microcrystals of xylitolwith a solid fatty substance in a proportion of 0.5 to 15 parts byweight of fatty substance to each 100 parts by weight of xylitol. Thefatty substance is preferably a mono-, di- or triglyceride having amelting range of between 20° and 60° C.

U.S. Pat. No. 3,389,000 to Toyonaka et al. discloses protective coatingsfor granular nucleoside-5-phosphates, the coatings being edible fatsmelting between 40°-100° C. and derived from plants and animals.Examples of edible fats include hydrogenated oils such as soybean oil,cottonseed oil, almond oil, castor oil, linseed oil, mustard oil, oliveoil, grapefruit seed oil, palm oil, palm kernel oil, rapeseed oil, ricebran oil and the like and mixtures thereof. This reference discloses aprocess of preparing the granular product from a liquid mixture of fatsand nucleoside-5-phosphates which are sprayed from a pressure nozzle andthe resultant granules cooked and recovered.

U.S. Pat. No. 4,382,924 to Berling discloses liquid oral dosage formsfor vitamins or pharmaceutical materials comprising an edible oil, ahigh potency lipid soluble sweetener such as saccharin and a lipidsoluble flavorant. The edible oil may be a polyol fatty acid esterhaving at least four fatty acid ester groups and each fatty acid havingfrom about 8 to about 22 carbon atoms. The oil, sweetener and flavor oilare mixed and heated and then cooled to provide a palatable liquiddosage form.

For a general discussion of spraying fatty materials onto sweeteners andthe like, see U.S. Pat. Nos. 3,949,094 and 3,976,794 both to Johnson andU.S. Pat. No. 3,867,556 to Darragh et al. U.S. Pat. No. 4,293,572 toSilva et al. discloses the application of a dispersion of an emulsifiedfat with a solution of dextrin, saccharin or a polysaccharide to a foodproduct as a barrier against moisture. U.S. Pat. No. 3,527,647 disclosesa process of agglomerating particles by randomly scattering and sprayingmoistened particles to cause them to collide and form agglomerates.

The problem relating to stabilization of sweeteners such as aspartame,which has not been previously addressed, relates to the wettability ofthe aspartame crystal as well as to its morphological configuration. Asa result, it is very difficult to coat aspartame using ordinary mixingor spray coating techniques. To be effective as protective barriers,coatings must be able to wet and adhere to the crystalline surface,including the needle-like tips and other shape variations of theaspartame. Additionally, the coating must be capable of being applied ina film with a uniform thickness sufficient to provide a barrier againstdegradative factors such as moisture, pH changes, temperature changesand reactive chemicals. The coatings, in addition to being protectivebarriers, must be flexible enough to conform to the surfaceirregularities and geometrical configuration without cracking due tomechanical stresses which it is subjected to during incorporation of thesweetener into specific product applications.

One approach has been to mix known coating materials such as fats, withcertain other core materials such as aspartame, however the notedcoating materials do not provide adequate protection to keep the corematerial in a stabilized state. Fats do not provide adequate coatingmaterials, nor do such coating materials as starch and certain othermaterials such as waxes. Many of these materials require solvents andmoisture for application, which have adverse effects on the stability ofhydrophilic instable materials such as aspartame.

The process of European patent application No. 81110320.9 (PublicationNo. 0053844) filed Dec. 10, 1981, discussed above, is an example ofadmixing of coating materials with aspartame. This publication disclosesthe melting and admixture of from 20 to 60% of solid fat, 10 to 30% ofpolysaccharide and not more than 30% dipeptide sweetener. The mixture isthen cooled and pulverized or spray dried. The pulverizing into finepowder, however, results in rupturing of the coating, leaving theaspartame exposed. Spray drying is normally associated with the drivingoff of moisture or solvents.

U.S. Pat. No. 4,597,970 discloses a delivery system wherein a sweeteneris coated with a mixture of fatty acid or wax, lecithin andmonoglyceride. The delivery system of this reference discloses a methodof protecting the sweetener as well as providing controlled release.

The prior art techniques for coating difficult-to-coat materials such asaspartame has focused on two methods. The first method involves theformation of a molten mixture of the coating material with thesweetener. The mixture is then solidified by cooling and pulverizing.The resultant particles represent a random attempt at completely coatingor enrobing the sweetener. In the case of aspartame, this coating doesnot provide adequate protection against moisture or aldehyde-containingflavor oils and instability of the aspartame results.

The second conventional prior art technique for coating materialsinvolves fluidized bed spray coating. This technique involves suspendinga mass of the material to be coated into a stream of atomized dropletsof coating material. In the case where this process is employed withuncoated materials such as aspartame, this method is very difficult.Aspartame is a low density material, has a large surface to weight ratioand poor wetting characteristics.

In our co-pending application Ser. No. 945,743, it was proposed toprepare a sweetener delivery system comprising a sweetener such asaspartame dispersed in a melted and blended mixture of a low molecularweight polyvinylacetate and an emulsifier. The resulting dispersion isthen cooled to ambient temperature and hardened, and thereafter groundto the desired particle size. Optionally, the particles thus preparedwere coated with a hydrophobic mixture comprising a fat or wax blendedwith an emulsifier to provide, in effect, a discrete second coating tothe sweetener composite. While the resulting composite exhibits improvedstability, particularly when the subsequent coating of the fat/waxmixture is employed, the application of the latter coating tended tofurther delay sweetness release. This additional delay of release isundesirable in certain products, such as chewing gums and otherconfections, where a more immediate sweetness release is desired.

A further drawback in the use of the fat/wax second coating is thatsubstantial amounts of this coating must be applied to the core particleto provide the required protection to the sweetener, particularly in theinstance where the sweetener is aspartame. Thus, it has been foundnecessary to apply fat/wax coatings of about 300% by weight of theinitial low molecular weight polyvinylacetate coating to confer thedesired stability to the sweetener. The application of a coating of suchthickness, even by the improved spray congealing methods utilized, is arelatively complex and involved procedure which naturally adds to thecost of the resulting product and consequently to products into whichsuch sweetener composite may be incorporated.

A last concern respecting the composites prepared in accordance withco-pending application Ser. No. 945,743 by the incorporation of asubsequent coating of fat/wax, relates to the high temperaturesensitivity of such a resulting composite. In particular, the fat/waxcoating is more temperature sensitive and therefore the resultingsweetener composite cannot be employed in certain products such as bakedgoods or hard candies where higher processing temperatures are involved,without some concern that the outer coating of the composite will meltand thereby increase the risk that the sweetener will be attacked andbroken down.

A need therefore exists for the preparation of a composite sweetenerdelivery system that can provide better stability to the sweetener witha greater initial sweetness release in combination with the delayedsweetness sensation conferred by the polyvinyl acetate core, all infurther conjunction with improved stability including stability at hightemperatures.

SUMMARY OF THE INVENTION

It has been discovered that a sweetener delivery system can be madeusing a multiple coating system comprising a first or core coatingformed from the combination of an emulsifier with low molecular weightpolyvinyl acetate and a second outer coating prepared from a hydrophilicpolymer. This multiple coating system provides improved resistance toattack from the flavor component when the present delivery system isincorporated into a chewing gum, and improved stability to hightemperatures. When applied to sweeteners such as aspartame, thesecoatings effectuate sustained release of the sweetener, therebyextending the period of sweetener perception and enjoyment of thechewing gum or confection while at the same time enhancing the initialintensity and experience of sweetness release. The sweetener deliverysystem of the present invention can be used in both sugar gums and insugarless gum formulations.

Accordingly, the sweetener delivery system of the present inventioncomprises:

A. At least one solid natural or artificial high intensity sweetenerselected from the group consisting of amino acid-based sweeteners,chloro derivatives of sucrose, dihydroflavinol, hydroxyguaiacol esters,L-aminodicarboxylic acid gem-diamines, L-aminodicarboxylic acidaminoalkenoic acid ester amides, dipeptide sweeteners, glycyrrhizin,saccharin and its salts, acesulfame salts, cyclamates, steviosides,talin, dihydrochalcone compounds and mixtures thereof;

B. An emulsifier selected from the group consisting of lecithin,stearates, ester derivatives of stearates, palmitates, ester derivativesof palmitates, oleates, ester derivatives of oleates, glycerides, esterderivatives of glycerides, sucrose polyesters, polyglycerolesters, andanimal waxes, vegetable waxes, synthetic waxes, petroleum wax andmixtures thereof;

C. A first coating of polyvinyl acetate present in amounts of about 20%to about 93% by weight of the total composition and having a molecularweight of about 2,000 to about 14,000 and preferably about 2,000 toabout 12,000; and

D. An outer coating of a hydrophilic polymer in an amount of from about5% to about 50% by weight and preferably from about 15% to about 50% byweight of the first coating.

The combination of polyvinyl acetate and aforementioned emulsifiers andthe outer hydrophilic coating produces a coating system that formsexcellent films on the sweeteners. The core coatings are substantiallywater-insoluble and thus protect the sweetener or other encapsulatedmaterial form hydrolytic degradation. Yet, the core coatings possesssufficient hydrophilic character to swell in the presence of water,thereby slowly releasing the core material. The outer hydrophiliccoating confers the combined advantages of more rapid disintegration andcorresponding acceleration of sweetener release while at the same timeproviding improved heat stability and resistance to sweetener breakdownfrom flavor attack.

Of the emulsifiers useful in the preparation of the core coating of thepresent invention, glyceryl monostearate is the most preferredemulsifier. Other advantages of the core coating can be enumerated. Forexample, the coatings are non-cariogenic; the method of making thedelivery system does not employ the use of solvents; the delivery systemcan be used in chewing gum, confectioners, personal product orpharmaceutical application where it is desirable to prolong delivery ofthe sweetener and to improve the stability of the sweetener byminimizing the interaction of the sweetner with both the flavor andmoisture. Other advantages of the instant invention will become apparentfrom a review of the ensuing description which proceeds with referenceto the following illustrative drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The FIGURE is a graph of the results of comparative chew panel testingof gum containing the inventive sweetener delivery system and thesweetener delivery system having an outer coating of fat.

DETAILED DESCRIPTION

The delivery system is prepared by melting the desired ratios ofpolyvinyl acetate and emulsifier and mixing them at a temperature ofabout 85° C. for a short period of time, e.g., 5 minutes or more. Oncethese materials are sufficiently melted and a homogenous mixture isobtained, the proper amount of solid sweetener is added and blended intothe molten mass thoroughly for an additional short period of mixing. Theresultant mixture is a semi-solid mass which is then cooled to obtain asolid, e.g., at 20° C., and ground to a U.S. standard mesh size of about30 to about 200 (600-75 microns).

Thereafter the particles are coated with the second coating of thepresent invention. The second coating material is a hydrophilic materialand is preferably a hydrocolloid. The hydrocolloid may be selected fromthe group consisting of gum arabic, gelatin, carrageenan, polyvinylpyrrolidone, cellulose, methylcellulose, ethylcellulose, hydroxyethylcellulose, hydroxypropyl cellulose, carboxymethyl cellulose, andmixtures thereof. Naturally the foregoing materials are representativeof suitable hydrocolloid coatings that may be used in accordanceherewith, and the invention is not limited thereto.

The second coating may be applied in an amount ranging from about 5.0%to about 50% by weight of the first coating, and preferably from about15% to about 50% by weight. It is one of the advantages of the presentinvention that the second coating can provide improved protection forthe active and at the same time enhance up front sweetness release, andyet is applied and is present in an amount that is substantially reducedfrom the fat/wax coating that is presently in successful use as theouter coating for the polyvinylacetate-encapsulated core material.

The application of the second outer coating to the core particle may beaccomplished by the same techniques disclosed in U.S. Pat. No. 4,384,004to Cea et al. for materials of this type, and accordingly a variety ofcoating techniques including spray drying, and fluidized bed coatingprocedures are useful. The preferred coating procedure is the fluidizedbed procedure wherein particles of the core material are suspended in anapparatus that creates a strong upward air current or stream in whichthe particles move. The stream passes through a zone of finely atomizedcoating material which causes the passing particles to be coated, afterwhich the coated particles move from the upward stream and traveldownward in a fluidized condition countercurrent to a flow of heatedfluidized gas whereupon they are dried. The particles may reenter theupward stream for a further coating or may be withdrawn from the coatingapparatus. The foregoing method and apparatus are known as the WursterProcess and are set forth in detail in the following U.S. Patents, thedisclosures of which are incorporated herein by reference: U.S. Pat. No.3,089,824; U.S. Pat. No. 3,117,027; U.S. Pat. No. 3,196,827; U.S. Pat.No. 3,241,520; and U.S. Pat. No. 3,253,944.

The application of the second coating may be conducted at temperaturelevels that are reduced from those of most encapsulation processes andare accordingly less likely to damage the treated particles. Inparticular, the second coating process may operate at inlet temperatureson the order of 100° to 125° F., so that relatively mild heating of theparticles takes place during the coating process. Naturally, thetemperature may vary and the selection of an optimum temperature resideswithin the skill of the art.

The second coating material is prepared for use by the formation of aliquid capable of being uniformly atomized. Thus, the water solublehydrocolloid materials may be prepared as aqueous solutions. If desired,other ingredients such as plasticizers may be added to improve theproperties of the final coating. Suitable plasticizers include theglyceryl ester of sebacic acid, diethyl phthalate, glyceryl triacetate,tributyl citrate, acetylated monoglyceride, citric acid ester ofmonodiglyceride, adipate ester, and others. The plasticizers may beadded in known effective amounts within the scope of the invention.

The instant delivery system can be incorporated in a number ofingestible products such as confections and the like, as well as chewinggum compositions, pharmaceutical preparations and denture products.

The resultant product of this invention is in powder or granulated form.The particle size is not critical to the delivery system and can beadjusted to accommodate a particular desired release rate and mouthfeel,depending on the vehicle, e.g., chewing gum, confection orpharmaceutical in which it is incorporated. The product can be used asis for various applications, e.g., as a topping on baked goods or as anadditive in a denture adhesive. The coating matrix is useful for avariety of core materials in addition to sweeteners, such as spray driedflavors, drugs and other particulate materials which require a coatingfor protection, controlled release or for taste-masking.

The core material can be selected from a wide variety of materials suchas sweeteners, medicaments, drugs, flavoring agents and the like. Thesematerials can be used either singly or in combination in either a singleor multiple delivery system. That is, one or more of these materials maybe present within one coating matrix or separately coated by the matrixand employed alone or in combination in a final product.

The sweetener component may be selected from solid natural or syntheticsweeteners capable of imparting high intensity sweetness. Thesesweeteners are selected from the group consisting of amino acid-basedsweeteners, chloro derivatives of sucrose, dihydroflavinol,hydroxyguaiacol esters, L-amino dicarboxylic acid gem-diamines,L-aminodicarboxylic acid aminoalkenoic acid ester amides, dipeptidesweeteners, glycyrrhizin, saccharin and its salts, acesulfame salts,cyclamates, steviosides, talin, dihydrochalcone compounds and mixturesthereof.

The sweeteners which are part of the delivery system may be used inamounts necessary to impart sweetness and preferably in amounts of about0.01 to about 30% by weight of the delivery system. Aspartame,saccharin, acesulfame and its salts are the preferred sweeteners and maybe used in amounts of about 0.01% to about 50% and about 0.01% to 50%,respectively, by weight of the delivery system. The preferred amounts ofthese sweeteners are about 2 to about 25%, most preferably about 5 toabout 15%. Auxiliary sweeteners may be used in the final product, i.e.,chewing gum composition, in conventional amounts standard in theindustry.

A particularly effective combination of sweeteners is aspartame, sodiumsaccharin and acesulfame K (potassium acesulfame). Saccharin and itssalts and acesulfame salts may be employed in amounts of about 5 toabout 50% by weight of the delivery system. Aspartame is used in amountsup to about 15% by weight when used in this combination. One or more ofthe sweeteners may be in the encapsulated form prior to incorporation inthe delivery system, thus delaying the release of the sweetener andlengthening the perceptible sweetness and/or staggering their release.Thus, the sweeteners may be incorporated such that they releasesequentially.

It has also been discovered that the incorporation of the combination oftwo or more sweeteners used alone or as part of the delivery systemimproves the sweetness intensity as a result of synergism. Exemplaryexamples of synergistic combinations are: saccharin/aspartame;saccharin/potassium acesulfame; saccharin/aspartame/potassiumacesulfame. These sweeteners can also be added to the final food,confectionery, drug or personal product independently of the deliverysystem. Thus, a good product may have sweetness imparted theretoattributable to the delivery system sweetness as well as those auxiliarysweeteners independent of the delivery system. These combinations ofsweeteners have also been discovered to impart a long-lasting flavoreffect to the food product such as chewing gum.

Useful flavoring agents may be chosen from synthetic flavoring liquidsand/or liquids derived from plants, leaves, flowers, fruits, etc., andcombinations thereof. Representative flavoring liquids include:spearmint oil, cinnamon oil, oil of wintergreen (methylsalicylate) andpeppermint oils. Also useful are artificial, natural or synthetic fruitflavors such as citrus oil including lemon, orange, grape, lime andgrapefruit and fruit essences including apple, strawberry, cherry,pineapple and so forth.

The amount of flavoring agent employed is normally a matter ofpreference subject to such factors as flavor type, base type andstrength desired. In general, amounts of about 0.05% to about 3.0% byweight of the final chewing bum composition are usable with amounts ofabout 0.3% to about 2.5% being preferred and about 0.7% to about 2.0%being most preferred.

With regard to chewing gum formulations in which the novel deliverysystem is employed, the amount of gum base employed will vary greatlydepending on various factors such as the type of base used, consistencydesired and other components used to make the final product. In general,amounts of about 5% to about 85% by weight of the final chewing gumcomposition are acceptable for use in chewing gum composition withpreferred amounts of about 15% to about 70% by weight. The gum base maybe any waterinsoluble gum base well known in the art. Illustrativeexamples of suitable polymers in gum bases include both natural andsynthetic elastomers and rubbers. For example, those polymers which aresuitable in gum bases include, without limitation, substances ofvegetable origin such as chicle, jelutong, gutta percha and crown gum.Synthetic elastomers such as butadienestyrene copolymers,isobutylene-isoprene copolymers, polyethylene, polyisobutylene andpolyvinylacetate and mixtures thereof are particularly useful.

The gum base composition may contain elastomer solvents to aid insoftening the rubber component. Such elastomer solvents may comprisemethyl, glycerol or pentaerythritol esters of rosins or modified rosins,such as hydrogenated, dimerized or polymerized rosins or mixturesthereof. Examples of elastomer solvents suitable for use herein includethe pentaerythritol ester of partially hydrogenated wood rosin,pentaerythritol ester of wood rosin, glycerol ester of wood rosin,glycerol ester of partially dimerized rosin, glycerol ester ofpolymerized rosin, glycerol ester of tall oil rosin, glycerol ester ofwood rosin and partially hydrogenated wood rosin and partiallyhydrogenated methyl ester of rosin, such as polymers of alpha-pinene orbetapinene; terpene resins including polyterpene and mixtures thereof.The solvent may be employed in an amount ranging from about 10% to about75% and preferably about 45% to about 70% by weight to the gum base.

A variety of traditional ingredients such as plasticizers of softenerssuch as lanolin, stearic acid, sodium stearate, potassium stearate,glyceryl triacetate, glycerine and the like, for example, natural waxes,petroleum waxes, such as polyurethane waxes, paraffin waxes andmicrocrystalline waxes may also be incorporated into the gum base toobtain a variety of desirable textures and consistency properties. Theseindividual additional materials are generally employed in amounts of upto about 30% by weight and preferably in amounts of from about 3% toabout 20% by weight of the final gum base composition.

The chewing gum composition may additionally include the conventionaladditives of flavoring agents, coloring agents such as titanium dioxide;emulsifiers such as lecithin and glyceryl monostearate; and additionalfillers such as aluminum hydroxide, alumina, aluminum silicates, calciumcarbonate, and talc and combinations thereof. These fillers may also beused in the gum base in various amounts. Preferably, the amount offillers when used will vary from about 4% to about 30% by eight of thefinal chewing gum.

In the instance where auxiliary sweeteners are utilized in addition tothose in the delivery system, the present invention contemplates theinclusion of those sweeteners well known in the art, including bothnatural and artificial sweeteners. Thus, additional sweeteners may bechosen from the following nonlimiting list: sugars such as sucrose,glucose (corn syrup), dextrose, invert sugar, fructose, and mixturesthereof, saccharine and its various salts such as the sodium or calciumsalt; cyclamic acid and its various salts such as the sodium salt; thedipeptide sweeteners such as aspartame; dihydrochalcone compounds,glycyrrhizin; Stevia Rebaudiana (Stevioside); chloro derivatives ofsucrose; dihydroflavinol; hydroxyguaiacol esters; L-amino dicarboxylicacid gem-diamines; L-aminodicarboxylic acid aminoalkenoic acid esteramides; and sugar alcohols such as sorbitol, sorbitol syrup, mannitol,xylitol, and the like. Also contemplated as an additional sweetener isthe nonfermentable sugar substitute (hydrogenated starch hydrolysate)which is described in U.S. Reissue Pat. No. 26,959. Also contemplated isthe synthetic sweetener3,6-dihydro-6-methyl-1-1,2,3oxathiazan-4-one-2,2-dioxide, particularlythe potassium (Acesulfame-K), sodium and calcium salts thereof asdescribed in German Pat. No. 2,001,017.7.

Suitable flavorings including both natural and artificial flavors, andmints such as peppermint, menthol, artificial vanilla, cinnamon, variousfruit flavors, both individual and mixed, and the like are contemplated.The flavorings are generally utilized in amounts that will varydepending upon the individual flavor and may, for example, range inamounts of about 0.5% to about 3% by weight of the final chewing gumcomposition weight. The flavorings may be present in the deliverysystem, in the chewing gum composition itself, or both.

The colorants useful in the present invention include the pigments suchas titanium dioxide, that may be incorporated in amounts of up to about1% by weight, and preferably up to about 6% by weight. Also, thecolorants may include other dyes suitable for food, drug and cosmeticapplications, and known as FD&C dyes and the like. The materialsacceptable for the foregoing spectrum of use are preferablywater-soluble. Illustrative examples include indigoid dye, known as FD&CBlue No. 2, which is the disodium salt of 5,5'-indigotindisulfonic acid.Similarly, the dye known as FD&C Green No. 1 comprises atriphenylmethane dye and is the monosodium salts of 4-[4-N-ethyl-p-sulfobenzylamino)diphenylmethylene]-[1-(N-ethyl-N-p-sulfoniumbenzyl)-2-5-cyclohexadieneimine].A full recitation of all FD&C and D&C and their corresponding chemicalstructures may be found in the Kirk-Othmer Encyclopedia of ChemicalTechnology, in Volume 5, pages 857-884, which text is accordinglyincorporated herein by reference.

The chewing gums of the invention may be in any form known in the art,such as stick gum, slab gum, chunk gum, shredded gum, hardcoated gum,tableted gum, as well as center-filled gum.

The process of preparing the inventive chewing gum compositions is asfollows. The gum base is melted (about 85° to about 90° C.), cooled to78° C. and placed in a pre-warmed (60° C.) standard mixing kettleequipped with sigma blades. The emulsifier is then added and mixed in.Next, a portion of the sorbitol and the glycerin is added and mixed infor an additional 3 to 6 minutes. The mixing kettle is cooled andmannitol, and the remainder of the sorbitol and glycerin are then addedand mixing is continued. At the time, the unflavored chewing gumtemperature is about 39°-50° C. Flavor oil is then added andincorporated into the base and the mixing is continued. Finally, thedelivery system containing the sweetener material is added and mixed foran additional 1 to 10 minutes. The delivery system is added as the lastingredient. The final gum temperature is about 39° C.-50° C. The chewinggum composition is then discharged from the kettle, rolled, scored andformed into chewing gum pieces.

Accordingly, a further embodiment of the present invention relates to amethod of preparing a chewing gum composition having improved sustainedsweetener release properties which comprises:

(1) Preparing a sweetener delivery system wherein the sweetener isprotected by an encapsulation prepared by the process comprising:

(a) entrapping a sweetener in a polyvinyl acetate coating comprising thesteps of melting and blending the polyvinyl acetate with an emulsifierand dispersing the sweetener uniformly therein; cooling the mixture atambient temperature while continuing to mix;

(b) grinding the resultant mixture to the desired particle size;

(c) coating the resulting particles with a second coating material by afluidized bed-type process; and

(d) recovering the final plural coated particles; and

(2) Adding the resultant delivery system to a homogeneous mixture of agum base and remaining chewing gum ingredients; and

(3) Forming the resultant mixture into suitable chewing gum shapes.

The following examples serve to provide further appreciation of theinvention but are not meant in any way to restrict the effective scopeof the invention. All percentages throughout the specification are byweight percent of the final delivery system unless otherwise indicated.

EXAMPLE 1

Chewing gum compositions were prepared in accordance with the presentinvention for the purpose of comparing the improved properties ofextended sweetener release with the sweetener release of gumcompositions prepared within conventional parameters of ingredients andproportions as exemplified by Parent application Ser. No. 945,743, thedisclosure of which is incorporated herein by reference.

Accordingly, two compositions having the sweetener delivery system ofthe present invention were prepared and are designated Samples 1 and 3.The cores of Samples 1 and 3 were prepared in accordance with theteachings of the '743 application. Two compositions were prepared ascontrols with similar cores. All of the cores differed from each otheronly in the specific carbohydrates in their formulation, although eachcore contained approximately the same total amount of carbohydrateingredient. Each of the controls designated Samples 2 and 4 possessed anouter coating of 300% by weight of a fat in accordance with theteachings of the '743 Application. The proportions of ingredients ofSamples 1-4 are listed in Table 1, below.

                  TABLE 1                                                         ______________________________________                                                  AMOUNT (WEIGHT PERCENT)                                                       Examples                                                            INGREDIENT  #1      #2      #3     #4    #5                                   ______________________________________                                        Gum Formula                                                                   Gum Base    27.0000 27.0000 27.0000                                                                              27.0000                                                                             65.0000                              Carbohydrates/                                                                            59.7668 55.3426 59.6796                                                                              55.3426                                                                             25.7668                              Polyols                                                                       Softeners   9.5000  9.5000  9.5000 9.5000                                                                              5.5000                               Color       0.0490  0.0490  0.0490 0.0490                                                                              0.0490                               Flavor      2.0108  2.0108  2.0109 2.0108                                                                              2.0108                               Encapsulations                                                                NES-5*      1.6734  --      --     --    1.6734                               Elastomer Coated**                                                                        --      6.0976  --     6.0976                                                                              --                                   NES-8***    --      --      1.7606 --    --                                   ______________________________________                                         *Elastomer core with 15% gelatin coating                                      **Elastomer core with 300% fat coating                                        ***Elastomer core with 12.7% gelatin and 2.5% Tween 80 coating           

EXAMPLE 2

Comparative blind chew panel testing was conducted with Samples 1 and 2of the chewing gum compositions prepared in Example 1 above.

The test samples of gum were given to a chew panel whose members allchew on a regular basis, for the purpose of screening the samples.During the experiment, each panelist was asked to evaluate theprototypes by the attributes listed below and to render an opinion basedon the following numerical scale: ##STR1##

The panelists were asked to rate the samples at intervals of 30 seconds,2, 6, 10 and 15 minutes. The attribute rated was sweetness intensity.

The results of the ratings assigned by each of the panelists to each ofinventive Sample 1 and control Sample 2 were averaged together and thencompared as to sweetness intensities and delivery. The data areexpressed in graphical form in the FIGURE.

As can be seen from the FIGURE, the sample of the invention offered agreater initial sweetness intensity and continued to offer greatersweetness throughout this same period. The results of this testillustrate the improved stability of the inventive sweetener deliverysystem.

EXAMPLE 3

In this experiment, three gum formulations were prepared and tested tocompare the stability of the present sweetener delivery system with twoformulations prepared in accordance with the teachings of Parentapplication Ser. No. 945,743. In particular, it was sought to confirmthat the present formulation with as little as 15% by weight of thesecond hydrophilic coating would provide at least comparable stabilityto that conferred by the application of the fat coating in the amount of300% by weight.

Accordingly, the three formulations, all prepared with aspartame as thesweetener, comprised a first inventive formulation, a second formulationwith the elastomer encapsulated core alone, and a third formulation withthe elastomer encapsulated core coated with 300% by weight of theelastomer of a fat. Each of the particulate sweetener delivery systemswas incorporated into an identically formulated cinnamon flavoredchewing gum and then subjected to laboratory aging and testing. Thecinnamon flavor was chosen because it exerted the greatest destructiveeffect on the sweetener. The results are set forth in Table 2, below.

                  TABLE 2                                                         ______________________________________                                        Temperature = 30° C.                                                                 WEEKS                                                                         0    2        4      8                                          ______________________________________                                        Dual Encapsulation                                                                            2500   1632     1380 810                                      Elastomer Core  2500   1138     751  712                                      Elastomer 300% Coat                                                                           2500   1545     1327 1020                                     ______________________________________                                    

From the above Table, it is apparent that the inventive delivery systemperformed favorably by comparison with the fat coated sweetener systemand far better than the system comprising the elastomer core alone. Theinventive system is able to provide comparable protection to thesweetener with a far thinner second coat which, by its hydrophilicproperties, provides advantageous release characteristics.

This invention may be embodied in other forms or carried out in otherways without departing from the spirit or essential characteristicsthereof. The present disclosure is therefore to be considered as in allrespects illustrative and not restrictive, the scope of the inventionbeing indicated by the appended claims, and all changes which comewithin the meaning and range of equivalency are intended to be embracedtherein.

What is claimed is:
 1. A chewing gum composition capable of releasingincreased amounts of sweetness evenly over a prolonged release timecomprising a gum base and a sweetener delivery system capable ofmodulating sweetener release and providing greater protection for thesweetener, said sweetener delivery system comprising:A. at least onesolid natural or artificial high intensity sweetener selected from thegroup consisting of amino acid-based sweeteners, chloro derivatives ofsucrose, dihydroflavinol, hydroxyguaiacol esters, L-aminodicarboxylicacid gem-diamines, L-aminodicarboxylic acid aminoalkenoic acid esteramides, dipeptide sweeteners, glycyrrhizin, saccharin and its salts,acesulfame salts, cyclamates, steviosides, talin, dihydrochalconecompounds and mixtures thereof; B. an emulsifier selected from the groupconsisting of lecithin, stearates, ester derivatives of stearates,palmitates, ester derivatives of palmitates, oleates, ester derivativesof oleates, glycerides, ester derivatives of glycerides, sucrosepolyesters, polyglycerolesters, and animal waxes, vegetable waxes,synthetic waxes, petroleum wax and mixtures thereof; C. a first innercoating of polyvinyl acetate present in amounts of about 20% to about93% by weight of the total composition and having a molecular weight ofabout 2,000 to about 14,000; and D. a second outer coating of ahydrophilic polymer in an amount of from about 5% to about 50% by weightof said first coating.
 2. The chewing gum composition of claim 1,wherein said sweetener is present in an amount of from about 0.01% toabout 50% by weight of the delivery system.
 3. The chewing gumcomposition of claim 1 wherein said sweetener comprises aspartame in theamount of from about 0.01% to about 50% by weight of the deliverysystem.
 4. The chewing gum composition of claim 1 wherein said sweetenercomprises saccharin and its salts in the amount of from about 0.01% toabout 50% by weight of the delivery system.
 5. The chewing gumcomposition of claim 1 wherein said sweetener comprises a combination ofup to about 25% of aspartame and about 1.0% to about 50% of saccharinand its salts by weight of the delivery system.
 6. The chewing gumcomposition of claim 5 wherein the sweetener additionally contains about0.01% to about 50% of potassium acesulfame by weight of the deliverysystem.
 7. The chewing gum composition of claim 1 wherein saidemulsifier is present in an amount of from about 0.5% to about 20% byweight of the delivery system.
 8. The chewing gum composition of claim 1wherein said second coating comprises a hydrocolloid.
 9. The chewing gumcomposition of claim 8 wherein said hydrocolloid is selected from thegroup consisting of gum arabic, gelatin, carrageenan, polyvinylpyrrolidone, cellulose, methylcellulose, ethylcellulose, hydroxyethylcellulose, hydroxypropyl cellulose, carboxymethyl cellulose, andmixtures thereof.
 10. The chewing gum composition of claim 1 whereinsaid second coating is present in an amount of from about 15% to about50% by weight of said first coating.
 11. The chewing gum composition ofclaim 1, wherein said polyvinyl acetate has a molecular weight rangingfrom about 2,000 to about 12,000.
 12. The chewing gum composition ofclaim 7, wherein the emulsifier is selected from the group consisting ofglyceryl monostearate, glyceryl distearate, glyceryl tristearate, thefatty acid esters thereof, and mixtures thereof, and is present inamounts of about 2% to about 15% by weight of the delivery system. 13.The chewing gum composition of claim 11, wherein the polyvinyl acetateis blended with a material selected from the group consisting of resins,rosins, terpenes, elastomers, waxes and mixtures thereof.
 14. Thechewing gum composition of claim 1, wherein the gum base comprises anelastomer selected from the group consisting of natural rubber,synthetic rubber and mixtures thereof.
 15. The chewing gum compositionof claim 14, wherein the gum base elastomer is selected from the groupconsisting of chicle, jelutong, balata, gutta-percha, lechi-capsi,sorva, butadienestyrene copolymers, polyisobutylene,isobutylene-isoprene copolymers, polyethylene, polyvinylacetate, andmixtures thereof.
 16. The chewing gum composition of claim 15, whereinthe gum base is present in amounts of about 5% to about 85% by weight ofthe final chewing gum composition.
 17. The chewing gum composition ofclaim 1 further including fillers, coloring agents, flavoring agents,softeners, plasticizers, elastomers, elastomer solvents, sweeteningagents and mixtures thereof.
 18. A method of preparing a chewing gumcomposition having improved sustained sweetener release properties whichcomprises:(1) preparing a sweetener delivery system wherein thesweetener is protected by an encapsulation prepared by the processcomprising:(a) entrapping a sweetener in a polyvinyl acetate coatingcomprising the steps of melting and blending the polyvinyl acetate withan emulsifier and dispersing the sweetener uniformly therein; coolingthe mixture at ambient temperature while continuing to mix; (b) grindingthe resultant mixture to the desired particle size; (c) coating theresulting particles with a second coating material by a fluidized bedprocess; and (d) recovering the final plural coated particles; and (2)adding the resultant delivery system to a homogeneous mixture of a gumbase and remaining chewing gum ingredients; and (3) forming theresultant mixture into suitable chewing gum shapes.
 19. A method forpreparing a delivery system for sweeteners, comprising:(1) preparing asweetener delivery system wherein the sweetener is protected by anencapsulation prepared by the process comprising:(a) entrapping asweetener in a polyvinyl acetate coating comprising the steps of meltingand blending the polyvinyl acetate with an emulsifier and dispersing thesweetener uniformly therein; cooling the mixture at ambient temperaturewhile continuing to mix; (b) grinding the resultant mixture to thedesired particle size; (c) coating the resulting particles with a secondcoating material by a fluidized bed process; and (d) recovering thefinal plural coated particles; and (2) adding the resultant deliverysystem to a homogeneous mixture of a gum base and remaining chewing gumingredients; and (3) forming the resultant mixture into suitable chewinggum shapes.
 20. A confection including the sweetener delivery system ofclaim 1.